Fig. 1: Outcome comparison of HCMV infection in different cell lines.

a Immortalized renal proximal tubular cells (RPTECs) were infected with the HCMV TR strain (MOI of 1 PFU/cell) and observed for up to eight days post infection (8 dpi) by phase contrast micrographs. The black arrows indicate syncytia formation. HFFs and ARPE-19 cells were also included as positive controls and infected with the HCMV TR strain at MOI 0.5 and 3, respectively. Mock cells were used as negative controls. Scale bars, 250 μm. b Comparison of viral protein expression in RPTECs, ARPE-19 and HFFs upon HCMV infection. Protein lysates from RPTECs, ARPE-19 and HFFs infected as in (a) and harvested at different days post infection were subjected to immunoblotting using antibodies recognizing immediate early (IEA: IE1 and IE2), early (UL44), or late (pp28) viral antigens or anti-β-actin to show equal loading. c Representative indirect immunofluorescence on paraformaldehyde-fixed RPTECs, ARPE-19 and HFFs infected with HCMV for the indicated time points and stained with primary antibodies against IEA, UL44, and pp28 (green fluorescence). Cell nuclei were visualized by DAPI (blue). Scale bars, 200 μm. d The percentage of infected cells displaying expression of IEA (at 2 dpi), UL44 (4 dpi) and pp28 (6 dpi) was determined for all cell lines. The values were normalized to the total number of DAPI-positive cells. Image analysis was conducted using LAS X software (Leica Microsystems) and values are expressed as mean ± SD (error bars) relative to three different experiments, one of which is shown in C. e The production of viral particles in RPTECs, ARPE-19, and HFFs infected with HCMV TR as in (a) was measured by plaque assay on HFFs. At 4 and 6 dpi, viral plaques were microscopically counted and expressed as PFU/mL. Values are expressed as mean values ± SD (error bars) from three independent experiments.